1. Field of the Invention
The present invention relates to an animal trap entrance device for attachment to a container, so as to form an animal trap.
2. Description of the Prior Art
It is well known that small animals, such as rats, mice and other rodents, will push objects out of their way with their noses while searching for food. Consequently, ball-type animal traps generally take advantage of this tendency by providing a ball which can be "nosed" along a predetermined path to gain access to bait, but which will also cut off an exit route. Such traps are well known in the art and have been used for many years. Early designs typically incorporated a ball placed on an inclined track, which when disturbed by an animal entering the trap, would roll down the track to seal the animal's only escape route. However, these early designs were typically "one shot" designs, requiring that the ball be manually reset to the top of the track each time the trap was used. Consequently, these traps could only capture a single animal at a time.
For example, British Patent No. 17,092, issued to Webber on Oct. 8, 1891, discloses an early inclined plane ball trap, which when triggered, causes a ball to roll down an inclined plane to block the trap entrance. The ball must be manually reset to the top of the inclined plane after each use.
More advanced designs oriented the track so that the traps would be automatically reset after each use. For example, U.S. Pat. No. 944,926 issued to Turnbo on Jan. 4, 1909, discloses a ball type rat trap incorporating a pivoting platform on which a ball rolls to block the exit of a trapped animal. The trap includes a series of interlocking chambers which, in combination with the pivoting platform, provides for the automatic resetting of the trap and thus the trapping of multiple animals.
More recent developments include the use of a ball and inclined tube. For example, U.S. Pat. No. 3,681,869 issued to Barker on Aug. 8, 1972, discloses an animal trap including a box, an inclined tube mounted in the box and a ball located inside the tube. An animal entering one end of the tube rolls the ball up the inclined tube to gain access to the trap compartment through an aperture in the tube. Once the animal enters the trap compartment through the aperture, the ball rolls back to the initial position, blocking the animal's escape.
Notwithstanding the low cost and simplicity of design advantages that the ball and tube traps offer over earlier designs, they are not without their disadvantage. All of the ball and inclined tube configurations are based on free rolling movement of the ball within the inclined tube to trap the animal. However, trapped animals tend to defecate abundantly inside the trap and tube, which eventually impedes the free rolling motion of the ball within the tube. In the worst case, the trap will no longer automatically reset and may not even prevent the escape of trapped animals. Moreover, the clogged tubes can be difficult to clean, particularly when they are permanently attached to the animal container or permanently integrated into the trap.
In addition to the problems caused by clogged tubes, a trapped animal can be difficult to remove from a trap when the ball and inclined tube are permanently attached to the container in which the trapped animal is held. Trapped animals will often re-enter the tube when the trap container is opened, making their removal particularly difficult.
Finally, all these prior art traps include both the entrance mechanism and the animal container. However, virtually every household has many soft drink containers, which could hold an animal if a mechanism existed for trapping an animal into the container.
Consequently, an animal trap entrance device which can be attached to a disposable container to form an animal trap, which is inexpensive and simple to manufacture, which will automatically reset after capturing an animal and which does not rely on the rolling movement of a ball within a tube is highly desirable.